The general purpose of the present program project grant is to gain a more accurate understanding of the physiology of speech misarticulation and to improve diagnosis and management of speech articulatory disorders through instrumental procedures. The goal for the present series of studies is to document the physical characteristics of /s/ and /sh/ sound production by normal speakers and misarticulation of those sounds by speakers who lisp and speakers who are deaf. Studies will also be carried out using instrumental feedback to help speakers with articulation disorders identify and change erroneous speaking patterns. The goal in that instance will be to find stimulus and response strategies that have a high probability of helping speakers improve their articulation. Finally, background studies will be done to develop an accurate description of the shape of the roof of the mouth in normal speakers and also to determine the effect of prosthetic devices of varying thickness on speech articulation patterns. BIBLIOGRAPHIC REFERENCES: McCutcheon, M.J., Fletcher, S. G. and Hasegawa, A., Video-scaaning system for measurement of lip and jaw motion. J. Acoust. Soc. Am. 61:1051-1056, 1977. McCutcheon, M. J., Hasegawa, A. and Fletcher, S. G., Abstract. Measurement and analysis techniques for the description of palatal shape. J. Acoust. Soc. Am. 61:S31, 1977.